How to Make Dies For Hydraulic Press

Hydraulic presses bridge the gap between industrial blanking processes and hand sawing by producing identical pieces faster than you can saw them - as well as creating intricate shapes impossible to cut with shears.

Beginning your sculpture starts with creating a model. This could be anything from a plastic ring, wood piece, wax or plaster model.

Basics

Hydraulic presses can generate up to 20 tons of pressure and allow you to shape and stamp metal without breaking it or bending it, with applications including forming, punching and deep drawing. You'll find hydraulic presses at most machine shops or metal fabricating businesses; they come in various sizes as well.

A basic press consists of a matrix die and punch. A punch is a special die that cuts out the shape of a blank or piece of metal being formed; its mold, the matrix die, is attached to a flat base material like wood, masonite, or plexiglass for easy assembly. Any leftover Devcon B from pouring conforming dies can also be placed into containers before curing, so any extra material can be used to carve or file punches later on.

Utilizing a punch and flexible matrix to form metal can reduce the work involved with hammer forming while producing forms that are difficult to accomplish through other means, such as etched or roll printed pieces with wires appliqued. Furthermore, this approach results in an uninterrupted surface without hammer marks for easier repoussage.

Materials

Hydraulic presses are powerful and costly tools, requiring special dies made of metal or pourable epoxy-steel for use with extreme amounts of pressure. Nickel-chromium metal alloy is often the choice to ensure long-term durability of these dies.

Die types include punching (punching many identical holes of equal size and shape, usually round but can also take any form) and cutting or shearing (the act of taking material away from blanks or parts already formed). Piercing refers to creating openings such as holes or slots in sheet material, plates or parts.

Simple dies perform one operation per press slide stroke and are ideal for shaping work pieces without needing precision or detail. More sophisticated dies may be used for coining, embossing or bulging; these techniques may be employed on an individual artist-metalsmith level as form boxes.

Design

Die forming is not widely employed in metalsmithing due to the time and money required for creating dies as well as its daunting nature - it requires both muscle power and precise instructions from a hydraulic press operator!

To create a permanent, reusable die for your hydraulic press, begin with a scale drawing of the shape you intend to form and Lexan plastic (which resists shatter). Center your shape on one plate and carefully scribe a line around its outline. Cut out this cutout shape, keeping its edges straight with perpendicular sides - this becomes the matrix, or female portion, of your die.

When creating a male-female die, leave more space than required in the matrix for your desired molded shape. This will enable metal to flow down around it more freely and help avoid distortion of the die. Furthermore, placing a thin sheet of wax to reflect its thickness over the matrix could slow the rate of wear on its forming surface of mold molds.

Assembly

Hydraulic presses generate full pressing force throughout their stroke for precise control, making them ideal for applications such as piercing, coining and embossing.

Customized hydraulic presses can also be used to alter metal pieces by forcing them through male and female dies, without intentionally reducing thickness, to alter their shapes. This process is known as "forming".

Create your desired form in plexiglass, wax or plaster to serve as the "matrix" for a conforming die. Saw out your design from brass or steel sheet, keeping the area that was sawed away for later reversibility of die. File all edges smoothly keeping them straight and perpendicular to faces and choose your urethane with care: 80 durometer is more flexible while 95 durometer provides stronger starting density when pushing into tight corners.